Archive for the ‘Uncategorized’ Category
Why, exactly, is the square root of 2 not a rational number?
Posted by: Gary Ernest Davis on: December 3, 2010
Right angled triangles and The Pythagorean theorem tells us that a square erected on the hypotenuse of a right-angled triangle will have an are equal to the sum of the areas of squares erected on the other two sides: In particular, a right-angled triangle with the two sides adjacent to the right angle having length […]
The value of cos(pi/5)
Posted by: Gary Ernest Davis on: December 3, 2010
@capedsam Tweeted: “Can you find an exact value for cos(pi/5)? “ x It is actually fairly easy to find an exact value for by following a path through the complex numbers. x To do this we use Euler’s identity for all real numbers . x Jim Tanton (@jamestanton) has a very nice introduction to Euler’s […]
